In certain applications, it is desirable for separate electrical circuits or even separate groups of electrical circuits to be arranged so that if one group of circuits is switched to a conductive state, another group of circuits is switched to a non-conductive state in alternating fashion. For example, separate loads may be alternately connected and disconnected with either a common power source or separate power sources. In other arrangements, it may be desirable to alternately switch a common load between separate power sources so that as one power source is disconnected from the load the second power source is simultaneously connected to prevent any interruption of power to the load. So that the desired pattern of alternate switching may be effected essentially simultaneously, a need has been recognized for a coupling mechanism which operates to switch one group of circuits off as the other group of circuits is switched on.
Applications in which separate circuits or separate groups of circuits are protected by circuit breakers coupled for alternate switching, it is desirable that all of the separate groups of circuits have the capability to be switched to non-conductive states during the same time period. Proper safety precaution mandates that the capability exist for the separate circuit breakers to be turned off at the same time to permit, for example, a common load which is alternately connected with separate power sources to be safely serviced or repaired. Consequently, in applications where a selected pattern of alternate switching of separate groups of circuits is desired for circuits protected by separate circuit breakers, it is desirable for a coupling mechanism to have the capability of permitting either circuit breaker to switch off without affecting the conductive state of the other circuit breaker.
In accordance with the present invention, a mechanism is provided which automatically turns one circuit breaker off when an adjacent circuit breaker is turned on. The mechanism in accordance with the present invention assures that the main contacts of both circuit breakers cannot be closed at the same time. The mechanism of the present invention does permit, however, both of the circuit breakers to be switched off at the same time.